For your first example, the interrogative "where" would fit:
Where is your pen.

Your second example could have more than one answer,depending on what the question is.

If you are asking whether someone who can help exists, you could say
Is there anyone who can help me make a database in Access?

If you are asking if there is anyone present who can help, you could say
Is there anyone here who can help...?

If you are asking for the location of a person who can help, you could say either
Where is there someone who can help...?
or, more likely,
Where can I find someone to help...?

Both examples could have different answers, depending on what you mean.

For your first example, the interrogative "where" might fit:
Where is your pen.
or you might mean
Is your pen here? or
Is this your pen?

For the second example,

If you are asking whether someone who can help exists, you could say
Is there anyone who can help me make a database in Access?

If you are asking if there is anyone present who can help, you could say
Is there anyone here who can help...?

If you are asking for the location of a person who can help, you could say either
Where is there someone who can help...?
or, more likely,
Where can I find someone to help...?